An observation conducted by a team of Steven S. Voght of the University of California at Santa Cruz, the team confirmed the existence of planet Gliese 581g. The planet is so special because according to astronomers, it is the planet's most livable alternative by humans.

The observational results are positive because the existence of Gliese 581g previous is in doubt. Though the findings on 29 September 2010 by the Lick-Carnegie Exoplanet Survey. However, HARPS team from the Geneva Observatory was unable to confirm the existence of the planet with the data they have.

Gliese 581g is a planet orbiting a red dwarf star Gliese 581. Gliese 581g distance is approximately 20.5 light years from Earth. Gliese 581g has a circular orbit, instead of an elliptical orbit as it has been believed.

Scientists of astronomy say Gliese 581g receives the light approximatly equal to that received by Earth. Index based on a livable scale of 0 to 1, Gliese 581g has an index of 0.92, being the most extrasolar planet habitable. The analysis also revealed that the Gliese 581g has a diameter 1.5 times larger than Earth.

As for the latest survey also shows some exoplanets are considered more livable such as Gliese 667Cc, Kepler-22b, HD85512 and Gliese 581d. With the confirmation of Gliese 581g, the planetary system Gliese 581 is the only candidate who has 2 habitable planet.